Sunday 11 December 2016 12.57 EST
First published on Sunday 11 December 2016 04.31 EST

Egypt has declared three days of mourning on Sunday after a bombing at a chapel adjacent to Egypt’s main Coptic Christian cathedral killed 25 people and wounded another 49.

Egypt’s state-run news agency Mena reported that 12 kilograms of TNT explosives were used in the attack. The majority of those killed were women and children.

There was no immediate claim of responsibility for the attack.

In a statement, President Abdel Fatah al-Sisi encouraged Muslims and Coptic Christians to band together “to emerge victorious in the war against terrorism, which is the battle of all Egyptians”. He stressed that the government would be harsh in its response to the attack, one of the deadliest carried out against the religious minority in recent years.

Those who pray regularly at St Mark’s Cathedral described a system of security within the compound that appeared strong, but could be lax. “People who commit such acts do so with impunity,” said one man, declining to be named as he stood close to the blast site and held up a small wooden cross. “There are normally police on both entrances to the cathedral and to the chapel.” Asked whether everyone who entered the cathedral compound was searched, he answered: “Sometimes yes, sometimes no”.

As the death toll rose and nearby hospitals called for blood donations, there was grief and anger in the streets. Hundreds of people crowded outside the cathedral, including a large crowd of young men who made clear their complaints against conservative Muslim groups, Egypt’s ministry of the interior and even the president. “As long as any Egyptian blood is cheap, down with any president,” they chanted.

“You ask for our emotions? Look in there,” said one man, pointing at the angry crowd. “What do you expect us to feel? People were killed while they were praying. They didn’t even die in their homes,” he said.

The Egyptian government has staked its mandate on the fight against Islamist groups as well as the Sinai chapter of Islamic State. Protecting the minority Christian population is the cornerstone of this pledge, but Sunday’s attack caused some to question whether the government is living up to its promise to provide security to all Egyptians.

“The government doesn’t protect us. They can’t protect us against terrorism in general,” said one man, who also wished to remain anonymous.

“Lots of Christians supported the current regime out of fear of being targeted by Islamist extremists,” said Mina Thabet, an expert on religious minorities at the Cairo-based Egyptian Commission for Rights and Freedoms. “Many Christians supported Sisi as he represented himself as a protecter of Christians against extreme groups. Today’s event may affect their support.”

Other members of the Coptic community were unshaken in their support for Egypt’s government.

“This is an injury to all Egyptians,” said Father Boules Haliem, spokesman for the Coptic Church of Egypt. “This is about more than the Coptic community, this is an attack on all Egyptians.”

Egypt has witnessed a rise in attacks by Islamist groups including those affiliated to Isis since the overthrow of former Islamist president Mohammed Morsi in 2013.

An attack close to a mosque in Giza on Friday killed six security officials, and was later claimed by a group named “Hasm”, or “Decisiveness.” The group, which the Egyptian government believes is a violent offshoot from the deposed Muslim Brotherhood group, issued a statement condemning Sunday’s attack via the encrypted messenger service Telegram, calling it an example of “dirty hands extending to churches to kill women and children”.